| Name | Meaning | Gender | Origin |
|---|
| Jaguar | Large Spotted Feline | Male | English |
| Java | Brewed coffee | Female | Anglicization |
| Jet | A deep black colour. Aircraft engine that propels an aircraft forward by expelling exhaust gases toward the rear. | Male | Mineral |
| Jethro | excellence | Male | Hebrew |
| Jett | Jet Black Gem | Male | English |
| Jinx | Charm, Spell | Female | Latin |
| Jupiter | Zeus, Father | Male | Roman |
| Knight | Noble, Soldier | Male | English |
| Krishna | dark, black | Male | Sanskrit |
| Kyo | Approval, Ginger, Or Large | Unisex | Japanese |
| Langston | Town Of The Giant | Male | English |
| Lava | Moulton Earth | Unisex | English |
| Leila | dark as the night | Female | Persian |
| Lestat | | Unisex | Hebrew |
| Licorice | Confection made from the licorice root. | Unisex | |
| Lightning | | Unisex | Hebrew |
| Loki | To Break | Male | Norse |
| Lucifer | light-bearer | Male | Latin |
| Lucifer | light-bearer | Male | Latin |
| Lucky | Having good luck. | Male | Word |
| Magic | Possessing qualities that produce baffling effects | Male | Word |
| Magic | Possessing qualities that produce baffling effects | Male | Word |
| Magnus | One who is great.
| Male | Latin |
| Magpie | | Unisex | |
| Manson | | Unisex | Hebrew |